Single-ply corrugated fabric and method of making the same



B. H. FOSTER 2,627,644

SINGLE-FLY CORRUGATED FABRIC AND METHOD OF MAKING THE SAME Feb. 10, 1953 2 SHEETSSHEET 1 Filed June 24, 1950 ATTORNEY Feb. 10, 1953 s. H. FOSTER 2,627,644

SINGLE-FLY CORRUGATED FABRIC AND METHOD OF MAKING THE SAME Filed June 24, 1950 2 SI-IEETS-SHEET 2 /4 I N V EN TOR.

3007714611 ffldfffl ATTORNEY Patented Feb, 1, 1953 'I'ES OFFICE SINGLE-FLY CORRUGATED FABREC AND IWETHGD 0F MNG THE SAME Application June 24, 1950, Serial No. 170,197

11 Claims. (Ci. 23-73) This invention relates to an all textile singleply corrugated fabric and method of making the same, and which is well adapted for use as rug underlay, ventilated seat covers and interlining for arctic clothing.

t is a relatively simple matter to make a single-ply corrugated fabric by passing a sheet of fabric between a pair of cooperating corrugated rolls or gears, but such fabric will not hold the corrugations.

The present invention contemplates a singleply corrugated fabric which is so constructed that the corrugations are firmly held by th fabric construction from flattening out and losing the corrugated shape. Such a fabric is capable of supporting a load of from 2 ozs. to 2 lbs. to the square inch, depending upon the properties desired in the fabric, without being compressed more than 50%. Furthermore a corrugated fabric constructed in accordance with the present invention and having the resistance to crushing just mentioned, is light in weight, simple to construct and inexpensive to manufacture.

The fabric employed to make this single-ply corrugated construction of the present invention may be a plain open weave fabric having a singleply construction throughout, and may have the weft yarns formed of cotton, rayon or other ordinary yarns but for many purposes it is desirable to employ dimensionally stable thermoplastic yarns throughout the weft.

It is important that the warp be formed of alternate rows of heat-shrinkable yarns and nonheat-shrinkabie yarns, the latter preferably being relatively stiff, dimensionally stable thermoplastic yarns. The alternate rows just mentioned may have the same or different widths, and each row may have anywhere from several to a dozen or more warp yarns to thereby form bands or strips extending lengthwise of the fabric.

If a single ply fabric having alternate rows of heat-shrinkable yarns and non-heat-shrinkable yarns extending lengthwise thereof, as just described, is heated sufficiently to shrink the heatshrinkable yarns to a substantial degree without controlling the contraction of the fabric, it will buckle and bend in an indiscriminat manner as it contracts so that the shrunken fabric will have no uniform appearance. Such a distorted fabric apparently would have very little practical use. On the other hand, if the fabric above described is subjected to a sufficient temperature to shrink the heat-shrinkable yarns under controlled conditions whereby the fabric is provided with evenly spaced transverse waves or undulations, a highly uniform corrugated fabric can be produced as the heat-shrinkable yarns contract and the adjacent non-shrinkable yarns assume uniform undulations. As soon as such corrugated fabric cools the shrunken warp rows will remain locked in their shrunken condition and will serve to prevent the undulated non-shrunken warp rows from straightening out under pressure and decreasing the undulations. It is this holding action of the heat-shrinkable rows that retains the undulated rows in their corrugated condition. .This produces a lightweight single-ply corrugated fabric having pronounced resistance to compression.

The fabric used in producing the corrugated construction of the present invention may be woven on any ordinary loom and is preferably a plain open weave fabric having its weft formed of any desired yarns that will not shrink under the heat treatment above-mentioned. The warp rows above-mentioned are formed alternately of heat-shrinkable yarns and non-heat-shrinkable yarns. The heat-shrinkable yarns may be oriented polyethylene monofilaments or multifilaments Vinyon yarns. The non-heat-shrinkable yarns are preferably formed of monofilaments of saran, nylon or similar thermoplastic resinous materials which will be softened to some extent by the above mentioned heat treatment, but are dimensionally stable at such temperature, and they should for many purposes be stiffer than ordinary textile yarns of the same size. Saran is a copolymer of vinylidene chloride and vinyl chloride containing less than 10% plasticizer. The finished single-ply corrugated fabric contemplated by the present invention may vary in thickness from about A of an inch to 1 inch or more, depending upon the use to which the fabric is to be put, and the weight of such finished corrugated fabric may vary from about 5 ounces per square yard for the finishedfabric having a thickness of A1 of an inch to about 40 ounces per square yard for a finished fabric having a thickness of 1 inch.

The above and other features of the corrugated fabric contemplated by the present invention and method of making the same will be further'under: stood from the following description when read in connection withthe accompanying drawings,

wherein Fig. 1 is a perspective view of one mbodiment of the ofi-the-loom fabric adapted to be corrugated in accordance with the present invention;v

Fig. 2 is a perspective view of the finished corrugated fabric produced from the oii-the-loom fabric of Fig. 1;

Fig. 3 on an enlarged scale is a sectional View taken on the line 3-3 of Fig. 2;

Fig. 4- is a similar view taken on the line :-=l of Fig. 2;

Fig. 5 is a view similar to Fig. *l but shows a iodified construction produced by varying the width of the warp rows;

Fig. 5 is perspective View showing a pair of long meshing gears employed to impart undulations to the fabric of Fig. l; and

Fig. 7 is a longitudinal sectional view through a tank containing hot water and the crimping gears of Fig. 6, and this tank is employed to heatshrink the fabric that is crimped by such meshing gears.

The fabric shown in all views but Fig. 5 is designated in its entirety by the numeral Hi. This fabric which as shown has a plain open weave is formed of the weft yarns i i that are the same throughout, and. of two difierent types of warp yarns arranged to form rows or strips extending lengthwise of the fabric as best shown in 1. The wef t yarns i' l are non-shrinkable yarns, such as saran or nylon that are dimensionally stable at the temperature use. lhe darker rows Fig. l are formed of relatively coarse stifl monofilament warp yarns 12 formed of thermoplastic resinous material such as saran or nylon and are e mers of returning, when heated, to a shorter ength from which it was drawn out at some previous stage in its manufacture. Examples of heat-shrinkable synthetic filaments that may be used are:

l. Vinyon, an oriented copolymer of vinyl chloride (88 to 90%) with vinyl acetate (10 to 12%) 2. An oriented polymerized ethylene (polyethylene).

Examples of non-heat shrinkable synthetic filaments that may be used are:

i. Saran, an oriented copolymer of vinylidene chloride with a small proportion (about 4 to 10 generally about 5%) of vinyl chloride;

2. Dacron, an oriented polyester of tercp-hthalic acid with ethylene glycol.

The warp yarns iii are shown much larger in the drawing than the warp yarns l3, but this will vary with the amount of stiiiness desired in the finished corrugated fabric. The fact that the yarns it are capable of contracting a large amount will be apparent upon comparing l with Fig. 2, as both figures are drawn to the same scale, and show the corrugated fabric as approximately half as long as the off-the-loom fabric of Fig. 1. This corrugated fabric is also slightly narrower than the fabric of Fig. 1 due to the bending of the weft yarns H in the corrugated fabric. This transverse shrinkage may be 10% or more.

The different yarns l2 and [3 may be introduced into the warp in various ways, for examplc a number of the non-shrinkable yarns it may be placed side by side to form a band or strip as shown. Alongside this strip are introduced in side by side relation 3. number of heat-shrinkable yarns 3 to form a band or strip, to thereby provide throughout the fabric alternate bands of heat-shrinkable yarns and non-heat-sln-inkable yarns. Fig. 2 shows that the corrugations are formed by the bands of non-shrinkable yarns l2, and that they are held in the corrugated or wavy condition by the bands of yarns l3 which are now shrunken and wave only slightly in the finished l'abric. In other words the bands formed of the yarns i3 assume a nearly straighty line position in the fabric, to perform their important function of preventing the waves of the bands formed of the yarns 52 from straightening out under crushing pressure. It will be noted from 2 that the heat-shrinkable yarns [3 contract less close to the heavier and stifier yarns l2 than they do near the centerof the heat-shrinkable bands.

In order to form the symmetrical corrugated fabric of Fig. 2 from the woven fabric of Fig. 1 it is necessary to heat treat the fabric of Fig. l and during such heat treatment to control or initiate the transverse waves where the corrugations are to be formed. The required heat may be supplied in various ways, but from a practical standpoint it is desired to use hot water maintained at a temperature of about 200 F. Fig. '7 shows a hot water tank having the bottom wall is, sloping end walls i5 and side walls It. This tank is provided with means, not shown, for maintaining the level of the water therein at the height indicated by the line W. The water is maintained at the desired temperature by any suitable means such as the steam pipes l? which preferably are provided with bleed apertures that will permit steam to escape from these pipes into the water to heat the same. Within this tank are rotatably supported near one end thereof the long cooperating gears l3 and IS that are longer than the fabric is wide and the teeth oi which mesh as shown. These gears are rotated at the desired speed by any suitable means not shown. Fig. 6 shows that the fabric decreases in width as the corrugation of the same increases. In the construction shown the fabric of Fig. l is led over a supporting bar or roller 29 to the gears IS and i9 where it is acted upon by the intermeshing teeth of these gears to crimp the fabric. These gears are heated, as the lower gear is entirely submerged in the water in the tank and the upper gear is partly submerged as shown. The engagement of the hot teeth of these gears with the fabric l6 will soften and render more flexible the saran warp threads i2 and the saran weft threads ii, if it is decided to use saran in the weft. The hot teeth will also soften the heat-shrinkable yarns l3 and cause them to start to shrink. r e fabric thus softened will conform readily to the action of the teeth of the gears I 8 and i9, which exert a crimping action upon the fabric but do not exert an injurious squeezing action upon the same. Since it is contemplated that the it will be advanced rapidly by the mech.-. shown in Fig. 7, the crimped fabric 1 quickly out from engagement with the and Ii. before it has taken a substantial amount of set, and therefore much of the crimp will disappear near these gears as shown in Figs. G and 7. However, as the fabric it is advanced lengthwise oi the tank below the level oi the hot water as shown the heat-shrinkable warp yarns 13 will continue to shrink under the action of the heat, and this will serve gradually to G increase the crimp or transverse waves of the fabric along the fold lines initiated by the crimping action of the gears 13 and it, to thereby gradually increase the formation of the desired corrugations as shown in Fig. 7. As the corrugated fabric approaches the discharge end of the tank it passes up over a supporting bar or roll 2i and leaves the tank as a finished corrugated fabric ready for the market. The amount the heat-shrinkable yarns l3 shrink will depend largely upon the temperature to which they are subjected. They will shrink a substantial amount in the hot water bath having a temperature of 200 F., but will shrink further if subjected to a higher temperature. Therefore when the fabric containing these yarns leaves the tank it such yarns are heat-shrinkable yarns that are shrunken a substantial amount but are capable of shrinking further.

If a fabric having its warp formed entirely of saran yarns should be passed through the heated crimping gears of Fig. '7, it would be transversely crimped or corrugated by such gears, but upon passing therefrom while still hot most of this crimp would disappear. Likewise if the fabric of Fig. 1 is passed between the hot crimping gears of Fig. 7 as shown it will be crimped but this crimp will largely disappear upon leaving such gears, but in this case the crimp will reappear as the yarns i3 contract and cause the yarns 2 to bend where they were previously crimped. This, as above stated, is illustrated in Figs. 6 and 7, which show that the depth of the waves or corrugations increase as the fabric advances in the hot water. The saran yarns are softened by the hot water so that they will bend easily, and when they are later cooled they will tend to retain the bend and waves they received in the tank.

The modified corrugated fabric shown in transverse section in Fig. is very similar to that shown in Figs. 2, 3 and 4 except that the rows or bands formed of the coarse saran warp yarns 22 are divided by several heat-shrinkable warp yarns 23. The other heat-shrinkable warp yarns 2 1 and weft yarns 25 are the same as in Fig. 2.

A single-ply corrugated fabric constructed as contemplated by the present invention is easy and inexpensive to make and is highly porous so that it has excellent ventilating properties when used as a seat or mattress cover, or as a mattress formed of several sheets of such corrugated fabric placed one on top of the other. It is very light in Weight, and if coarse saran warp yarns are used as the non-shrinkable yarns that form the corrugations it will have high resistance to crushing.

By the term mechanically, as used in the claims, I refer to a mechanical pressure means external to the fabric, for forming the precrimped barrier, e. g., by the use of mechanical corrugated rolls acting on the heat softened material.

Having thus described my invention what I claim and desire to protect by Letters Patent is:

1. A single-ply corrugated fabric having symmetrical corrugations that are stiff enough to support a, substantial load, comprising an open weave fabric of single-ply, throughout and formed of alternate rows of heat-shrinkable warp yarns and non-shrinkable warp yarns and of non-shrinkable weft yarns interwoven with both types of warp yarns, the non-shrinkable warp yarns being mechanically-initially crimped uniformly in the fabric along their lengths and said heat-shrinkable yarns being shrunken in the fabric sufficiently to hold the other warp.

yarns in an undulated condition to form a corrugated fabric that will not elongate appreciably under pressure.

2. A single-ply corrugated fabric having sym metrical corrugations that are stiff enough to support a load of at least one pound to the square inch without being crushed more than 50%, comprising an open weave fabric of single-ply throughout and formed of alternate rows of heatshrinkable warp yarns and non-shrinkable warp yarns and of non-shrinkable weft yarns interwoven with both types of warp yarns, the nonshrinkable warp yarns being mechanically-initially crimped uniformly in the fabric along their lengths and said heat-shrinkable yarns being shrunken in the fabric suficiently to hold the other warp yarns in an undulated condition to form a corrugated fabric that will not elongate appreciably under pressure.

3. A single-ply, highly ventilated, corrugated fabric, comprising an open weave fabric of singleply throughout and formed of alternate rows of heat-shrinkable warp yarns and relatively stiff non-shrinkable warp yarns and of non-shrinkable weft yarns interwoven with both types of warp yarns, the non-shrinkable warp yarns being inechanically-initially crimped uniformly in the fabric along their lengths and said heat-shrinkable yarns being shrunken in the fabric sufficiently to hold the stiff yarns in an undulated condition to form a corrugated fabric that will not elongate appreciably under pressure.

A single-ply corrugated fabric, comprising a fabric of single-ply throughout and formed of alternate rows of heat-shrinkable Warp yarns and non-shrinkable warp yarns forming bands lengthwise the fabric and having non-shrinkable weft yarns interwoven therewith, the non-shrinkable bands being mechanically-initially crimped uniformly in the fabric along their lengths and the heat-shrinkable bands being shrunken sufficiently to hold the adjacent non-shrinkable bands in an undulated condition to form a corrugated fabric that will not elongate appreciably under pressure.

5. A single-ply corrugated fabric having sym metrical corrugations and a thickness of at least one-fourth inch, comprising an open weave fabric of single-ply throughout and formed of alternate rows of heat-shrinkable warp yarns and nonshrinkable warp yarns and of non-shrinkable weft yarns interwoven with both types of warp yarns, the non-shrinkable warp yarns being mechanically-initially crimped uniformly in the fabric along their lengths and, said heat-shrinkable yarns being shrunken more than 25 in the fabric to hold the non-shrinkable warp yarns in an undulated condition to form a corrugated fabric that will not elongate appreciably.

6. A single-ply corrugated fabric, comprising a fabric of single-ply throughout and formed of alternate rows of heat-shrinkable warp yarns and saran warp yarns and of non-shrinkable weft yarns interwoven with both types of warp yarns, the saran warp yarns being mechanically-initially crimped uniformly in the fabric along their lengths and the heat-shrinkable yarns being shrunken more than 25% in the fabric to hold the saran warp yarns in an undulated condition to form a corrugated fabric.

7. The method of making a single-ply corrugated fabric having symmetrical corrugations,

which comprises weaving a single ply fabric having'extending lengthwise thereof alternate rows of heat-si'irinlzable warps and non-heat-shrinizable warps, passing this fabric longitudinally between meshing gears to crimp the fabric transversely, and heating the fabric so that the 1 eatshrinkable warps will contract cause the other warps to bend where crimped and form a symmetrical corrugated fabric.

8. The method of making a single-ply corrugated fabric, which comprises weaving a singleply fabric having extendin lengthwise thereof alternate rows of heat-shrinkable warps and nonheat-shrinkable warps, passing the fabric through meshing gears and hot water to crimp and heat the fabric so that the heat-shrinkable warps will contract and cause the other warps to bend where crimped and form symmetrical corrugations.

9. The method of makin a single-ply corrugated fabric having symmetrical corrugations, L

which comprises weaving a single ply fabric having extending lengthwise thereof alternate rows of heat-shrinkable warps and non-heat-shrinkable warps, mechanically-initially crimping the fabric transversely and by temporarily applying crimping pressure thereto, and heating the fabric so that the heat-shrinkable warps will cause the other warps to bend where crimped and form a corrugated fabric.

10. The method of making a single-ply open weave corrugated fabric having symmetrical corrugaticns of a substantial depth which comprises weaving a single-ply open weave fabric havin tending lengthwise thereof alternate rows of synthetic heat-shrinkable yarns and synthetic non-- heat-shrinkable stiff yarns, and interwoven with crossing yarns, preliminarily heat softening the yarns of the fabric and simultaneously passing fabric through crimping rolls to apply crimping pressure transversely thereto, and further heating the fabric so that the heat-shrinkable yarns will cause the said non-heat-shrinkable yarns to bend where crimped and form a corrugated fabric.

11. A single-ply open weave corrugated fabric having symmetrical corrugations of a substantial depth and formed from alternate rows of stiff synthetic non-heat-shrinkable yarns and synthetic heat-shrunken yarns interwoven with crossing yarns, the said non-shrinkable yarns of said fabric having predetermined mechanically-initially crimped areas uniformly spaced along their l ngth, said heat-shrunken yarns being shrunken in the fabric suiiiciently to bend the said nonshrinkable yarns at said predetermined mechanically criniped areas into a corrugated condition.

BOUTWELL FOSTER.

REFERENCES CITED The following references are of record in the fife of this patent:

UNITED STATES PATENTS NLilbel Name Date 369,275 Cumnock Aug. 30, 1687 1,512,236 Horton Oct. 21, 1924 1,512,287 Horton Oct. 21, 1924 2,022,391 Smith Nov. 26, 1935 2,213,125 Hubert et a Aug. 27, 1940 2,364, 2; Thomas Dec. 5, 1944 2,373,195 'Wedler Apr. 10, 1945 2,334,935 Lille et a! M Sept. 18, 194-5 55,391,950 Croft et a1 Jan. 1, 19 16 2,461,829 E'Zahii June 11, 1946 FOREIGN PATENTS Number Country Date 603,839 Great Britain June 23, 1948 

